The assembler source code of the startup code ./crt1/gcrt1.S -n could be added to the installation.

This makes it easier for the user to adjust the startup code and / or compiler it for devices that are not yet supported by avr-gcc as lined out in [http://gcc.gnu.org/wiki/avr-gcc#Supporting_.22unsupported.22_Devices avr-gcc Wiki: Supporting "unsupported" Devices].

The onyl dependency should be #include <avr/io.h>.

Other dependencies like macros.inc and sectionname.h can easily be avoided altogether, which makes using gcrt1.S more straigh forward.